Spring is here. Gardens are being planted, everywhere plants are flowering and the world is once again becoming green, so I thought it would be a fitting time to share some of my favorite things about one of the most dynamic, yet underappreciated systems on Earth, soil. First, it’s important to have a bit of a background on how and why soils formed and what that has meant to the evolution of modern human civilization. I’ll then describe some of the not-so good (and the good) news about what we have been doing to our soils in the recent past that is jeopardizing our ability to feed our growing world population and what many amazing soil scientists, farmers, gardeners, and involved citizens are doing about it.
Soil is a complex living, breathing system. It’s packed with tons of cool organisms and is an extremely complex mixture of inorganic and organic processes, without which life on Earth could not exist. Through industrial agricultural practices, urbanization and deforestation we are in danger of degrading our healthy soils by stripping off nutrient rich layers that are necessary for functioning ecosystems, and from a more anthropocentric perspective, for our ability to grow food.
To get a sense of just how important soil is we have to backtrack to the to the beginning of the first life on Earth, about 3.8 billion years ago, when the Earth’s average temperature was too hot and anoxic for anything except extreme cyanobacteria to survive. The presence of bacteria on rock surfaces helped to enhance weathering rates through chemical reactions, which sped up the breakdown of rocks and formation of soils. Carbon dioxide, an important greenhouse gas, diffused into soils to be used for various reactions, which helped to decrease its warming effect in our atmosphere. The slow breakdown of rocks and formation of soil minerals also created a suitable nutrient rich substrate necessary for the evolution of land plants. Through photosynthesis, plants further decreased carbon dioxide and increased oxygen levels in the atmosphere and then died and contributed organic matter to the soil. It wasn’t until about 400 million years ago that the first land plants appeared, and only a little while before that when soils came to be as we know them today.
Fast forward to about ten thousand years ago, when humans first began transitioning to more stationary, agricultural civilizations. Without any knowledge of genetics, we bred and domesticated plants to achieve higher yields. It was no longer necessary for everyone to grow food. People began to establish urban centers where new professions emerged and food was obtained from surpluses produced by a small subset of the population. Farmers have always understood that maintaining fertile soils is imperative to successful agricultural practices. But the advent of the Green Revolution in the 20th century led us astray, convincing us that science and technology were capable of going beyond the limits of traditional farming techniques.
The Haber-Bosch process, discovered in the early 20th century, led to the production of synthetic nitrogen fertilizers and drastically increased crop yields worldwide. That, along with the introduction of other technologies and the use of higher yielding crops led to the establishment of larger, industrialized agricultural systems. Our reliance on synthetic fertilizers to increase crop yields has so far allowed us to overlook the exquisitely complex systems in which plants grow best. Sure, for now we can give them lots of nitrogen and phosphorus and they will grow. But, without adding other forms of organic matter or manure to supply plants with nutrients and to feed bacteria, fungi and other organisms in the soil that provide essential ecosystem services, we are running a thin line between high yields and an inability to sustain the level of production that we have become accustomed to.
It seems like somehow in our urbanized, fast paced lives we have lost touch with nature and our ability to connect with the very thing that is essential for our survival and ability to feed our growing population. In a great documentary called DIRT, there was a scene describing an urban school that wanted to convert concrete playgrounds to vegetable gardens, but a journalist reporting on the story was worried that there would be nowhere for the children to play. I will never forget that twisted feeling I got as I realized just how disillusioned and frightened of the unpredictability of nature we have become. We often fail to understand how important a resource soil is, and desire to escape rather than embrace and appreciate the presence of soil in our daily lives.
I happen to live in a pretty rare suburban landscape. I have a natural greenbelt next to the river that runs through my neighborhood. As a kid, I remember being outside and playing in soil all the time. But it’s easy to imagine how living in urban landscapes allows many people to disconnect with nature, including more importantly I think, understanding where our food comes from. The emergence in popularity of farmers markets and community gardens are an indication that more people are making healthy and sustainable food a priority.
Now we must go one step further and make the connection to the bigger picture and understand that soils on a global scale are in danger. In some places, we are currently disposing of fertile soil to develop big suburban communities, complete with Wal-Marts, fast food chains and vast expanses of paved area that encourage us to forget how and why we got here in the first place. Soil erosion is a big problem in places where deforestation to make room for agricultural landscapes has destabilized and exposed soil to the elements so that it simply washes away. Monoculture farms that use large amounts of synthetic fertilizers to maintain high yearly yields contribute to the degradation of nutrients and biotic life in soils. Without maintaining bacterial and fungal communities that help plant roots to obtain essential nutrients, the food that we eat is not as nutritious.
It took billions of years to establish the delicate blanket of soil covering our planet that has provided us with the ability to develop complex agrarian civilizations. Yet, in a matter of a few generations we are well on our way to destroying one resource that we really can’t live without. It is encouraging to see that an awareness and desire for nutritious, organic food is growing in many urban areas. Permaculture, which designs agricultural systems to maximize efficient nutrient cycling and to maintain healthy ecosystems, is a philosophy for land management that is growing in popularity, particularly among young people looking to try farming or just urban gardening. However, it isn’t easy. Gardening takes lots of patience and practice and I’ve failed at it more times than I have succeeded. Even if you don’t have the room or desire to grow some of your own food, it is possible for everyone to contribute by attending farmers markets and supporting small-scale, local farms, that through grass-roots actions, are going to revolutionize the way we appreciate and value our food, soils and our place on Earth.
Now that spring is here, farmers markets will be starting up soon. Here’s a link to find farmers markets throughout BC.
http://www.bcfarmersmarket.org
A great website with tons of info and links to other great farming blogs as well:
http://www.permaculture.org/nm/index.php/site/index/
You can watch DIRT the movie free online here
http://www.truththeory.org/dirt-the-movie/
A good quick overview on the Green Revolution:
http://www.ifpri.org/sites/default/files/pubs/pubs/ib/ib11.pdf
